Generator



7 W. KAUTTER Sept. 10, 1935.

GENERATOR Filed April 25, 1931 AllAAA IIIIIII range.

Patented Sept. 10, 1935 UNITED STATES GENERATOR Wolfgang Kautter, Berlin-Charlottenburg, Germany, assignor to Siemens & Halske, Aktiengesellschaft, Siemensstadt, near Berlin, Germany, a corporation of Germany Application April 25, 1931, Serial No. 532,911 In Germany May 9, 1930 3 Claims.

For various practical uses, for instance, for measuring work, it is desirable to have available a continuous wave oscillator with which like amplitudes are producible inside a certain frequency In standard tube arrangements adapted to wave generation, the amplitudes vary with the frequencies. If the same amplitude is to be insured, it is necessary to re-set the back-feed or to alter the coupling means between the generator and the consumer or load. In order to overcome this inconvenience, circuit schemes have been suggested in which the regeneration is insured both capacitively as well as inductively. In the case of high frequencies, the capacitive influence predominates, while the same situation is true of the inductive influence in the presence of low frequencies. However, even in these circuit schemes it is not feasible to obtain even a roughly identical amplitude inside a somewhat large frequency range.

According to this invention, these difficulties are obviated by that in an arrangement for wave generation by the aid of thermionic tubes having capacitive regeneration means, the oscillation circuit governing the wave-length comprises an inductance and two series-connected condensers C1 and C2, the said condensers being actuated by the same drive means, and being equipped with plates of different shape or contour so that the aggregate capacity changes with the angle of rotation, whereas the relationship changes as a function of the angle of rotation and thus of the frequency in such a way that such a back-feed or reaction coefficient is adjusted and obtained that, no matter what the frequency inside a definite frequency range, the amplitude of the generated wave will always be the same.

The drawing by way of example shows an embodiment of such a scheme. A tube R is combined with a plate battery AB, a choke-coil D, a coil L and two condensers C1 and C2 in a way to result in wave generation. The ensuing capacity of the oscillation circuit which is formed by the coil L and the two series-connected and mechanically inter-coupled condensers C1 and C2, govern the wave-length of the oscillations produced by the generator tube. The reaction factor is independent of the relationship If both condensers C1 and C2 are increased, this means a growth of the resultant capacity, and the frequency decreases. By the suitable choice of the shape or contour of the plates of condensers C1 and C2 it is possible to make conditions so that 10 the reaction factor for any given position of the condenser is so dimensioned that the waves generated by the oscillator will have the same amplitude irrespective of the frequency.

Having thus described. my invention and the 15 operation thereof, what I claim is:

1. An audion oscillation circuit adapted to provide constant amplitude over a band of frequencies comprising a thermionic tube having a cathode and coupled input and output circuits, 2O tuning means in said circuits comprising an inductance connected in parallel relationship in respect of two serially connected condensers, a connection between said two condensers to the cathode of said tube, the rate of change of the 25 capacities of said condensers being variable at different rates, and unicontrol means for said condensers whereby upon movement thereof constant amplitude is obtained irrespective of the frequency in said band. 3o

2. An audion oscillation generator circuit adapted to provide constant amplitude oscillations within a predetermined frequency range having, in combination, a vacuum tube comprising a cathode, anode and control electrode, an in- 3 ductance connected across said anode and control electrode, two uni-controlled, series connected, variable plate condensers in parallel with said inductance, and a connection from a point intermediate said two condensers to said cathode, 40 said condensers having plates of dissimilar shape, the rate of change of capacity of said two condensers being so related as to maintain constant amplitude as said two condensers are varied to vary the frequency. 45

3. An oscillation generator circuit comprising a thermionic tube having an oscillatory circuit coupling its input and output together, two serially connected condensers having plates of dissimilar shape in said oscillatory circuit whose ag- 50 gregate value determines frequency and whose ratio determines oscillation strength, unicontrol means for varying said elements whereby movement thereof enables the ratio of the two elements to vary in a predetermined fashion with respect to the aggregate value thereof.

WOLFGANG KAUTTER. 

